George Harrison (guitar, sitar, vocals), John Lennon (guitar, keyboards, vocals), Paul McCartney (bass, guitar, keyboards, vocals), Ringo Starr (drums, percussion, vocals)The impact of the Beatles has often been noted but cannot be overstated. The "Fab Four" from Liverpool, England, startled the ears and energized the lives of virtually all who heard them. Their arrival triggered the musical revolution of the Sixties, introducing a modern sound and viewpoint that parted ways with the world of the previous decade.

The Beach Boys' vocal harmonies are among the most unmistakable and enduring of the rock and roll era. Among rock and roll groups of the Sixties, the California quintet place second only to the Beatles in terms of their overall impact on the Top 40. They were the Fab Four's most serious competitors on a creative level, too. Paul McCartney has allowed that the Beatles' masterpiece, Sgt.

Stevie Wonder was Motown's golden child. In his more than 30 years at Motown, Wonder has been a musical icon: first, as a child prodigy; second, as a young man with a soulful, maturing and multifaceted talent; and finally, as an adult driven by the challenge of realizing his ever-deepening inner visions. Over the course of his career, Wonder has been a true musical pioneer whose work has embraced influences as diverse as reggae and jazz. He created music that sounded startlingly fresh in the Seventies by bending synthesizer technology to his own funky, visionary ends.

Inductees: Bono (vocals; born May 10, 1960), The Edge (guitar; born August 8, 1961), Adam Clayton (bass; born March 13, 1960), Larry Mullen Jr. (drums; born October 31, 1961)From the beginning, U2 has been a band on a mission. With each album and concert, the Irish quartet has endeavored to create music of lasting worth and substance.

Inductees: Terry "Geezer" Butler (bass; born July 17, 1949), Tony Iommi (guitar; born February 19, 1948), Ozzy Osbourne (vocals; born December 3, 1948), Bill Ward (drums; born May 5, 1948)Black Sabbath is credited with creating heavy metal. The success of their first two albums - Black Sabbath and Paranoid - marked a paradigm shift in the world of rock.

Van Halen formed in 1974 but emerged in public view with the 1978 release of their self-titled debut album, which quickly established them as the hottest American hard-rock band since Aerosmith. Van Halen reinvigorated hard rock during a period of doldrums by bringing youthful, West Coast bravado and blistering virtuosity to the genre. Much of the latter was provided by Eddie Van Halen, who exhibited blinding speed, control and innovation on the guitar. His two-handed fretboard-tapping was just one technique that he introduced to legions of young guitarists.

Madonna is one of the most recognizable names in the world – and not just the world of music. She became the first multimedia pop icon, crossing from dance-oriented pop music into movies, television, videos, fashion and books while achieving a level of celebrity comparable to that of a primary inspiration, Marilyn Monroe. Madonna has been a ubiquitous and, at times, controversial figure since erupting on the scene with her debut single, Everybody," in 1982. No one in the pop realm has manipulated the media with such a savvy sense of self-promotion.

James Hetfield (vocals, guitar; born August 3, 1963), Kirk Hammett (guitar; born November 18, 1962), Jason Newsted (bass; born March 4, 1963), Lars Ulrich (drums; born December 26, 1963), Cliff Burton (bass; born February 10, 1962, died September 27, 1986), Robert Trujillo (bass; born October 23, 1964)Black Sabbath invented heavy metal in the Seventies, and Metallica redefined it in the Eighties. Since erupting on the scene with their debut album, Kill 'Em All, in 1983, Metallica has been a cutting-edge band – the standard by which metal's vitality and virtuosity are measured.

Michael Balzary aka Flea (bass; born October 16, 1962), John Frusciante (guitar; born March 5, 1970), Jack Irons (drums; born July 18, 1962), Anthony Kiedis (vocals; born November 1, 1962), Josh Klinghoffer (guitar; born October 3, 1979), Cliff Martinez (drums; born February 5, 1954), Hillel Slovak (guitar; born April 13, 1962, died June 25, 1988), Chad Smith (drums; born October 25, 1962)The Red Hot Chili Peppers created a synthesis of punk, funk, rock and rap to become one of the most popular and inventive groups of modern times.